Size and weight are big decision factors when you are trying to find the ideal camera for your needs.
In this section, we are going to illustrate the Sony A58 and Nikon P510 side-by-side from the front, back and top in their relative dimensions. Sony A58 has external dimensions of 129 x 95 x 78 mm (5.08 x 3.74 x 3.07″) and weighs 492 g (1.08 lb / 17.35 oz) (including batteries). Nikon P510 has external dimensions of 120 x 83 x 102 mm (4.72 x 3.27 x 4.02″) and weighs 555 g (1.22 lb / 19.58 oz) (including batteries).
Below you can see the front-view size comparison of the Sony A58 and the Nikon P510. Nikon P510 is 9mm narrower and 12mm shorter than Sony A58 but it is also 24mm thicker. As you can tell, actually this is not a fair size comparison since Nikon P510 has a built-in lens but Sony A58 doesn't. Once you put a lens on A58, its thickness will increase significantly.
Here is the back view size comparison of the Sony A58 and Nikon P510.
Now lets look at the top view comparison of Sony A58 and Nikon P510.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Sony A58 is 63g lighter than the Nikon P510 but we don't think this will make a significant difference.
Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on A58, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Sony SLT-A58 nor Nikon Coolpix P510 provides any type of weather sealing in their bodies, so you have to give extra care especially when you are shooting outdoors. If weather sealing is a must-have feature for you, check these sections: Top DSLR Cameras with Weather Sealing Top Bridge Cameras with Weather Sealing
LCD Screen Size and Features
Nikon P510's 3.00" LCD screen is slightly larger than Sony A58's 2.7" screen.